The Breitling Sion Air Show is a unique aeronautical spectacle in the heart of the Alps.
More visible and surprising, the airplanes become one with the mountains before they amaze and dazzle the spectators with their exhibitions.

As Popular Mechanics reporting on September 5, a U.S. Air Force aircraft crashed at the Nevada Test and Training Range (NTTR), killing the pilot. But even a week later, the Air Force has refused to reveal the type of aircraft involved in the incident. The hush-hush treatment has left many people wondering what the plane could be, and whether the Air Force is developing a new “black” aircraft that has not been declassified to the public.

The incident, which took place at a training facility in Nevada, has sparked speculation that some kind of previously unknown aircraft was involved. The pilot involved in the crash, Lt. Col. Eric Schultz, was a squadron commander of an Air Force unit that tests and evaluates foreign aircraft. If this is the case, the most likely explanation is that Schultz was piloting a foreign jet at the time of the crash.

Airmen who flight test foreign military planes, sometimes called Red Hats, are part of an unnumbered unit within Detachment 3 of the 53rd Test and Evaluation Group, stationed out of Nellis Air Force Base in Nevada. A press release from Nellis indicates that the aircraft involved in the incident belonged to Air Force Material Command, which oversees Detachment 3 of the 53rd. Flight testing foreign jets was previously conducted by the 413th Flight Test Squadron and the 4477th Test and Evaluation Squadron before that.

The exact aircraft type involved in the crash is still unknown, though it could be an Su-27 or possibly even the newer Su-30 multirole fighter, which Russia has sold to multiple U.S. allies such as Indonesia and Vietnam. Evaluating Russian aircraft has become a priority for the U.S. Air Force these days, as aerial encounters between the two militaries over Syria and the Baltics have become more common.

The mystery of the crash is compounded by the fact that Schultz was an experienced test pilot and engineer. A holder of six degrees, including a doctorate in aerospace engineering, Schultz had flown combat missions in the F-15E in Afghanistan and early flight test evaluations in the F-35, racking up more than 2,000 hours in a variety of aircraft over his career.